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References: <e8e73fcc-b902-4972-6001-84671361146d@datenfreihafen.org> <20220104182806.7188-1-paskripkin@gmail.com>
In-Reply-To: <20220104182806.7188-1-paskripkin@gmail.com>
From:   Alexander Aring <aahringo@redhat.com>
Date:   Tue, 4 Jan 2022 13:57:13 -0500
Message-ID: <CAK-6q+jkQqZ-Mog2Bwq2EGWFYv-vYtSYRJMqJUARm=C+Cd+uRA@mail.gmail.com>
Subject: Re: [PATCH v3] ieee802154: atusb: fix uninit value in atusb_set_extended_addr
To:     Pavel Skripkin <paskripkin@gmail.com>
Cc:     stefan@datenfreihafen.org, alex.aring@gmail.com,
        davem@davemloft.net, Jakub Kicinski <kuba@kernel.org>,
        linux-wpan@vger.kernel.org,
        Network Development <netdev@vger.kernel.org>,
        linux-kernel@vger.kernel.org,
        Alexander Potapenko <glider@google.com>
Content-Type: text/plain; charset="UTF-8"
Precedence: bulk

Hi,

On Tue, Jan 4, 2022 at 1:28 PM Pavel Skripkin <paskripkin@gmail.com> wrote:
>
> Alexander reported a use of uninitialized value in
> atusb_set_extended_addr(), that is caused by reading 0 bytes via
> usb_control_msg().
>
> Fix it by validating if the number of bytes transferred is actually
> correct, since usb_control_msg() may read less bytes, than was requested
> by caller.
>
> Fail log:
>
> BUG: KASAN: uninit-cmp in ieee802154_is_valid_extended_unicast_addr include/linux/ieee802154.h:310 [inline]
> BUG: KASAN: uninit-cmp in atusb_set_extended_addr drivers/net/ieee802154/atusb.c:1000 [inline]
> BUG: KASAN: uninit-cmp in atusb_probe.cold+0x29f/0x14db drivers/net/ieee802154/atusb.c:1056
> Uninit value used in comparison: 311daa649a2003bd stack handle: 000000009a2003bd
>  ieee802154_is_valid_extended_unicast_addr include/linux/ieee802154.h:310 [inline]
>  atusb_set_extended_addr drivers/net/ieee802154/atusb.c:1000 [inline]
>  atusb_probe.cold+0x29f/0x14db drivers/net/ieee802154/atusb.c:1056
>  usb_probe_interface+0x314/0x7f0 drivers/usb/core/driver.c:396
>
> Fixes: 7490b008d123 ("ieee802154: add support for atusb transceiver")
> Reported-by: Alexander Potapenko <glider@google.com>
> Acked-by: Alexander Aring <aahringo@redhat.com>
> Signed-off-by: Pavel Skripkin <paskripkin@gmail.com>
> ---
>
> Changes in v3:
>         - Changed atusb_control_msg() to usb_control_msg() in
>           atusb_get_and_show_build(), since request there may read various length
>           data
>

Thanks for catching this.

- Alex